Fix misplaced single-line PR-review suggestion anchoring

[JesperSchulz]

Problem

The Copilot PR Review orchestration (tools/Code Review/scripts/Invoke-CopilotPRReview.ps1) can anchor a suggestion block to the wrong line, so applying the suggestion corrupts the file.

Seen on #8893: a style suggestion (prefix the call with this., CodeCop AA0248) was anchored to a comment line (2196) instead of the statement it edits (2198). Auto-applying would overwrite the comment and leave the real call unprefixed.

Root cause

Resolve-SuggestionPlacement's single-line branch re-anchored only by exact whitespace-insensitive equality between the suggested line and a file line within ±8 of the model anchor. But a single-line suggestion almost always edits a line, so it is by definition not equal to the line it replaces (this. was inserted). No match was ever found, and the code fell through to "trust the anchor" — returning the model's unreliable line number, which pointed at a nearby comment.

Fix

• Re-anchor single-line suggestions by character-LCS similarity over a ±8 window. Pick the clear winner using an absolute confidence floor plus an ambiguity margin over the runner-up.
• When no candidate is confident/unambiguous, return $null so the caller suppresses the suggestion (posts a manual snippet) instead of trusting a wrong anchor — i.e. never produce an auto-applicable misplaced suggestion.
• Multi-line (additive-span) behaviour is unchanged.

Fixes AB#640948

[github-actions]

Copilot PR Review

Iteration 4 · Outcome: not-applicable

The diff contains no AL changes. The only changed file is a PowerShell script (tools/Code Review/scripts/Invoke-CopilotPRReview.ps1). All six sub-skills (al-performance-review, al-security-review, al-privacy-review, al-upgrade-review, al-style-review, al-ui-review) require technologies:[al] and returned not-applicable. The super-skill self-review pass also produced no findings as there is no AL code to analyse.

Knowledge source: https://github.com/microsoft/BCQuality@822cae1b2771ac25f665f73369f69093bd4fd630

No findings were posted for this iteration.

Orchestrator pre-filter (13 file(s) excluded)

• layer-disabled (knowledge) : 13 file(s)

_{Findings produced by the Copilot CLI agent against BCQuality at 822cae1b2771ac25f665f73369f69093bd4fd630. Reply 👎 on any inline comment to flag false positives.}